Possible strategies for converting their old ERP system

You are preparing to meet with your end users to discuss possible strategies for converting their old ERP system to a new one. Propose two (2) or three (3) alternative strategies, and explore related examples of situations for which each approach would be preferred and required. Outline the most common assumptions that developers usually make while documenting the initial use case realization. Determine whether or not there are negative consequences from such assumptions. Provide a rationale for your response.